|Reprinted from The
RSI Network - Issue 37 - Apr'99
Michael Roberts, B.App.Sci. (Physiotherapy)
With the increasing use of personal computers in homes and offices around the world, there is an increasing incidence of computer-related disorders, among them epicondylitis, carpal tunnel syndrome, De Quervain's tenosynovitis, extensor/flexor tenosynovitis, and others, also known as RSIs (repetitive strain injuries), RMIs (repetitive motion injuries), and OOS (occupational overuse syndrome). When the RSI epidemic swept the world in the late 1970s it was believed that the arm symptoms were coming from the wrists and forearms or from the complainants heads (i.e., "It's all in their heads.").
There are still many schools of thought on RSI. One that I believe has been under-rated is the role of posture, particularly in the neck, upper back, and shoulders. This area provides a stable platform from which the arms work. In computer work that platform is held fairly still for most working hours. If ones posture is erect, low muscle forces are required. But if people slump forward, or need to crane their necks over a badly set-up workstation, their muscles have to work hard and generate high forces to keep their heads from falling. Infrequent amounts of these high forces are no problem; it's when people repetitively and habitually crane forward that their muscles become fatigued and strained. This leads to what are known as static-loading injuriesstrained muscles from the overwork of holding for extended periods of time.
Why do the muscles become strained? Muscles require adequate blood flow to maintain performance. The pumping action of contract-relax-contract-relax is one way to maintain blood flow. In static working postures, however, muscles just contract and hold and hold and hold. This reduces blood pumping and flow. Good blood flow is critical for the operating muscle to bring in nutrients and remove waste products. If blood supply and waste removal are reduced, acids build up around the muscle fibres and lead to the pain you feel when someone kindly presses a thumb into your shoulder muscles and gives them a rub. Ouch!
Also, there are postural muscles and movement muscles. Whereas postural muscles are designed to hold for extended periods, movement muscles are ill-suited to this job. During computer work such as keying and using a mouse, you're asking many of your movement muscles to hold still, against their better naturelike telling a jiggling teenager to sit still in class. That's why we need to give the muscles something to do every so often, so they don't complain too much and decide to go on strike. Pause exercises are designed to fill this need (see Exercises, below).
But even postural muscles become tired when you maintain a poor posture. Make sure that your chair and workstation are set up to encourage an upright posture. If your screen is low and far away you'll poke your neck forward like a turkey. And if you leave the chair on the settings someone else used, then for you it's not an ergonomic chair. Many people haven't been taught the simple principles of how to adjust their workstation to enable them to sit in a healthy position at work. That's almost negligent when the desk and computer are tools of trade for every office worker.
These injuries started increasing as the mouse became a PC standard. I see three principal mouse injury causes:
1. Mouse position. Too many people use the mouse away from their bodies, forcing them to reach out slightly and bring their shoulder muscles into action unnecessarily. If the desk has a small keyboard tray that cant accommodate a mouse, then the mouse is likely to be up on the desktop, requiring greater shoulder action. When this situation occurs the shoulder is required to act frequently, resulting in fatigue and potentially a repetitive strain of some shoulder muscles. Keep the mouse close to your body and relax your shoulder while you use it. I often cut people's mousepad in half and slip it in next to the keyboard. After all, the big mousepad was designed in the 80s, when the mouse was far less responsive to movement.
2. Grip. Many people hold the mouse as tightly as if they were trying to land a space shuttle with it! Mice are delicate creatures, and need just a little gentle manipulation. Don't squeeze the life out of your mouse. Click the buttons lightly, then relax your handas if you were just nodding a mouse's head, not pinning it to the desktop and waiting for reinforcements. Your wrist and forearm should be relaxed, resting on the desk surface rather than unsupported and causing your shoulder to work.
3. The mousepad itself. Mousepads are renowned for losing contact and clogging the ball mechanism. I see so many office workers thrashing their mouse about as if in mortal combat. They unconsciously swear at the mouse but fail to stop and get better performance from the poor thing. Occasionally flip your mouse over and check it for indigestion: open up the trackball compartment and clean it. Swap your mousepad for a piece of split-skin suede leather. The difference in performance is incredible, and it feels so much better on your fingers.
A fascinating, in-depth review of exercises by six eminent ergonomists can be found in the December 1992 Applied Ergonomics, journal. They analysed the effectiveness of each exercise in 14 physical exercise programs for VDT users and office workers; most of the programs are widely known and globally available for purchase or distribution. The analysis involved close scrutiny of each exercise for the following categories: 1) effectiveness, 2) safety of "at risk" structures, 3) clarity of instructions, and 4) ease of performance. All six ergonomists agreed that many of the commonly prescribed exercises actually stretched or compressed "at risk" structures. Many of the exercises were judged to be ineffective, and many were thought to be too difficult to perform.
Early Warning Signs
There is no doubt that once contracted, RSI is a very difficult disorder to cure. Several of my current clients have ceased all keying and are having various professional treatments, yet are not recovering well at all. The major lesson I draw from their experience is that prevention is best and early warning signs must be heeded. Some of the most common early warning signs are: aching in the neck or shoulder blades while keying; tightness and soreness in the forearms; tingling in the fingers; muscle cramps in the neck, back, or shoulders while working; elbow discomfort, especially keying and mousing; tight/sore shoulder muscles.
Some Treatment Ideas
There are an infinite number of ways to treat RSI, many of which are unsuccessful. Anyone with symptomatic RSI should consult a doctor or physical therapist for advice. Anti-inflammatory medication might help in the short-term, but use it only if you are having other treatment or have modified your work practices. Don't use the drugs to press on, regardless of symptoms; give your body time to recover. Full soft-tissue healing takes at least six weeks, even though symptoms may disappear after two weeks. Make sure that the pain you felt or feel stimulates you to change something about the way you were working that lead to the problem in the first place.
Chiropractic or osteopathic treatment can help realign the spine and ease tension on the nerves. The goal of treatment should be to improve your posture and keep it that way. There's no sense just getting crunched and going back to work to slouch again. It may mean good repeat business for the chiropractor or osteopath, but it's courting disaster for you and your posture. Find a chiropractor or osteopath who will educate you and straighten you out, so to speak.
The best form of treatment includes variety and fun. If you can vary your work so that you don't spend large blocks of time in front of the computer, your risk of injury is greatly reduced. And if you're having fun, then your body will produce invincible happy hormones that protect you from anything, let alone a mouse and a keyboard! We intentionally made ErgoMinder fun to look at and use, to make it more likely to be followed. Also, we wanted to bust the paradigm that says posture is a boring and righteous subject.
About the Author
Last Updated: 11/03/00